Shock absorber



Sept. 1, 1931. F. w. DAVIS 1,821,142

SHOCK ABSORBER Filed Sept. 26, 1929 ATTOR N EY Patented Sept. 1, 1931FREDERICK N. DAVIS, OF KANSAS CITY,

MISSOURI; REBECCA .A. DAVIS ADIVIIN'IS- TRATREX OF SAID FREDERICK VJ'.DAVIS, DECEASED snoox AnsonBna Application filed. September 26, 1929.Serial No. 395,302.

My invention relates to shock absorbers and more particularly to devicesof this character employing a liquid, the principal objects of theinvention being to enable a shock absorber to function equally wellagainst stresses applied in opposite directions, to combine quick actingmeans responsive to slight shocks with means for absorbing heavy shocks,and to effect gradual reduction in a port through which liquid is movedupon operation of the device, and to increase the strength of aliquid-using shock absorber and thereby enhance its durability andimmunity to breakage and other damage.

In accomplishingthese and other objects of the invention, I haveprovided improved details of structure, the preferred forms of which areillustrated in the accompanying drawings, wherein; Y

1 is a perspective view of a portion of a vehicle including a spring anda frame member equipped with a shock absorber embodving my invention.

Fig. 2 is an enlarged detail perspective view of the improved shockabsorber'illustrating its members disassembled but in related position.Y I

Fig. 3 is an end View ofthe housing with the cover plate removed. anarcuate'partition shown in functioning position in'the housing, thepartition and rocking members being shown partly in section toillustrate the position of valve ports.

Fig. 4 is a section on the line 4%. 3 including a portion of a crank armfor connecting the shock absorber with the spring.

Referring in detail to the drawings: y

1 designates generally a portion of anautomobile, including an. axle 2,a frame member 3. a spring 4%. having ends connected with the framemember, and 5 designates U-bolts adapted to attach the spring to theaxle.

My invention includes a cylindrical housing or casing 6 having an openside and in cluding aback wall 7 having a bearing opening 8 and lateralears 9 whereby the housing may be secured tothe frame member 3. A coveror front platelO having a central bearing opening 11 is secured to theopen end of the housing to close the cylindrical chamber :1

12 formed thereby.

A shaftv 13 is rotatably mounted in the bearing recess and opening andprojects outwardly from the cover plate, and a crank arm 14 secured tothe projecting end of the shaft is connected by a rod 15 with a plate 16secured to the axle by the U-bolts so that when the spring moves withreference to the frame member, the rod will move vertically and operatethe crankarm and shaft.

The housing is adapted to contain liquid, for example oil, and a radialvane or blade 17 comprising a rocking arm having converging walls ispreferably formed integral with the shaft and has an edge 18 adapted forwiping engagement 'with the cylindrical inner periphery of the chamberas the blade rotates against the resistance of the liquid and atransverse opening or channel 19 whereby the blade may pass the liquid.

A sleeve-like U-shaped yoke 20 having an arcuate lower surface ismounted on the shaft and provided with ears or wings 21 havingsubstantially parallel inner faces 22 spaced from the inclined faces ofthe blade to form tapering compartments 23. The transverse edges of thewings move in wiping relation with the cylindrical inner periphery ofthe housing, and the vertical edges of theblade and the yoke move inwiping relation with the back wall and cover so that liquid is re tainedin theho'using and when the shaft-rm.

tates the blade moves toward one or another of the wings, liquid ineffect passing from one compartmentto another through the blade channel.1

An arcuate, preferably convex partition wall 24 is fixed to thecoverplate adjacent the bottom of the housing and extends across thechamber into sealing'engagement with the back wall 9 and cooperates withthe yoke to divide the chamber into opposite chamber portions 25 and26.The partition is'provided with a concave seat 27 at its apex with whichthe yoke is rotatably engaged to pre vent movement of liquid from onechamber portion to another between the yoke and the partition.

The partition comprises an arch forming with the lower portion of thehousing, a third chamber portion 28, and is provided with ports 29 and30 affording communication between the two main chamber portions and .26and the chamber portion 28 under conditions presently described. I

The end of the partition which engages the back wall is provided withapertures comprising notches 31 and 32 at the edges thereof which engagethe inner periphery of the housing comprising channels for movement ofliquid from a chamber 25 or 26 into the chamber 28 and a split rotatingring 33 is mounted in rotative sliding engagement with the back wall 7and the inner periphery of the housing, and extending in the notches ofthe partition.

The ends of the ring are spaced and en gaged with the outer end portionsof the wings of the yoke, whereby the yol e upon rotation will move thering in the casing.

The ring comprises a rotative circularly formed strip having portions ofdiffering area for controlling the effective area of the notches and forthis purpose its ends have greater width or diameter than itsintermediate portion, the effect being taat of forming the innerperiphery of the ring on a curve eccentric to the axis of the outerperiphery thereof. The ring halves taper symmetrically from their freeends to the point of juncture.

The ports 29 and in the partition are provided with valve cages 34 andvalve seats 35 for containing ball valves adapted to be opened outwardlyfor flow of liquid from the third chamber, a val e being seated to closea port when liquid is moved against it from of; of the main chamberportions, whereby flow is restricted to the notch that is related to theseated valve.

In operating a device constructed as described, rotation of the shaftand blade in either direction due to upward or downward movement of theconnecting rod will result'in propulsion of the liquid in correspondingdirection toward the partition. The symmetrical character of the membersand particularly of the partition enables the device to operate withequal efficiency in either direction.

The cooperating blade and winged yoke are particularly useful forabsorbing relatively slight shocks. When the shaft rotates responsivelyto a slight shock the blade will move rotatively and will be slightlyre- 1 strained due to the impediment of motion leecause of therelatively blade.

Should a relatively severe shock be transmitted the blade will firstmove toward one small opening in the of the wings of the yoke and effectan initial absorption of shock, and will then engage the wing and effectrotative movement of the yoke which in turn presses on the liquid in theadjacent chamber portion and forces the liquid through the correspondingnotch in the partition and into the third chamber below the archedpartition.

The liquid moves with relative diiiiculty through the small notch intothe arched chamber, displaces the valve in the opposite portion of thepartition, and may move with relative freedom from the arched chambersince it passes through a notch as well as through the valved port.

The rotating yoke also pushes the ring, which due to its taperingcharacter varies and gradually reduces the effective area of the notchopening first passed by the moving liquid. Resistance of the compressedliquid restricted by the relatively small area of the notch will usuallycheck the yoke and shaft beiore the widest portion of the ring reachesthe notch.

hen the strain or stress of the shock ceases and the frame and'springmove oppositely relative to each other, the shaft rotates in theopposite direction, the blade first taking'up the initial reversal shockby means of the liquid in the small tapering compart ments and thenengaging the winged yoke to move the same rotatively and propel theliquid reversely through the opposite notch of the partition, throughthe arched chamber and through the valved port and relatively open notchopposite to that through which the moving liquid enters the archedchamber.

Under such reverse operation of the device, the right hand notch isinitially reduced by the eccentric ring, but liquid is free to flowthrough the related valve port. A blade, yoke and ring approach normalposition, the right hand notch becomes more widely open so'that liquidmay flow more freely therethrough.

It is apparent that slight oscillations of the blade or of the blade andwings in either direction cause restrained movement of the liquid, thatthe initial movements are met by relatively slight resistance and that aplurality of factors for varying the degree of resistance at successivestages in the operation of the members in one direction are provided.

Attention is'particularly called to the fact that the ring affords amaximum passage or channel through a notch at the beginning of thepropulsion of liquid through the notch: and that when the action isreversed and the ring moves its thickened portion away from the notchthe effective opening of the notch increases gradually.

The size of the split ring will be initiallv adjusted to the notches inthe partition proportionately to the weight on the spri gs of a vehicleto which it may be applied. For example. in case of a relatively heavynormal load on the springs, the ring will be formed sufiiciently wide toprovide relatively small.

thus increase the resistance to the flow of liquid through thepartition. The blade cooperating with the wings of the yoke memher willin all cases provide for quick re sponse to relatively small shocks, andwill r turn promptly toward normal position.

Attention is called to the fact that theblade operates over a relativelysmall arc and the opening in the blade permits the same to moverelatively quickly through a small body of liquid in the compartments,when displacement of the frame and axle of the vehicle is slight, forpermitting free action of the metal springs of the vehicle, and yettakes the shock in both directions. When this limit of displacement isexceeded, the blade immediately engages the yoke wings, and urges themagainst the large body of liquid in the cas- 1n l Vhat I claim anddesire to secure by Letters Patent is:

1. In a shock absorber, a liquid containing housing, a blade rotatablein, the housing, a yoke mounted on the blade having limited freemovement relative to the blade and adapted to move the liquid, apartition dividing the housing into opposite portions and provided withan aperture for flow of liquid from one portion to the other, and meansmovable by said yoke for controlling the effective area of saidaperture.

2. In a shock absorber, a liquid containing housing, a blade rotatablein the housing, a yoke movable by said blade and adapted to move theliquid, a partition dividing the housing into opposite portions andhaving oppositely opening valve ports, the partition having aperturesfor free flow of liquid from one portion to the other, and means movableby said yoke for controlling the effective areas of said apertures.

3. In a shock absorber, a liquid containing housing, a blade rotatablein the housing, a yoke movable by said blade and adapted to move theliquid, a wall in the housing having apertures for flow of liquidpropelled by the yoke, and a split ring movable by the yoke in saidapertures to vary the eilective area of the same.

4;. In a shock absorber, a housing, a blade rotatable in the housing, ayoke movable by said blade and adapted to move the liquid, a wall in thehousing having apertures for flow of liquid in either direction underimpulse of the yoke, and a strip located in said apertures and movableby the yoke. said strip having portions of different size for varyingthe effective area of the apertures.

5. In a shock absorber including a liquidcont-aining housing, and ablade rotatable in the housing, a yoke movable by said blade and adaptedto move the liquid, a wall dividing the housing into opposite portionsand having openings for flow of liquid moved by the yoke from oneportion to the other, and a split ring havingopposite spaced endslocated adjacent the yoke and adapted to be moved thereby,

A shock absorber comprising a housing, a blade rotatable in the housing,awall dividing the housing into opposite portions and having openingsfor low of liquid moved by the blade from one portion to the other, anda strip having opposite ends located adjacent the blade and adapted tobe engaged thereby, said strip having an intermediate portion or" lesswidth than said ends extending in said openings, the ends being adaptedto reduce the ell'ective area of the openings upon rotation of theblade.

7. In a shock absorber, a housing having a cylindrical inner Wall, ablade mounted in the housing and having an edge slidable over said Wall,a yoke movable by the blade having wings spaced from the blade to formliquid containing compartments, and a wall in said housing dividing thesame into opposite portions and having openings for flow of liquid fromone portion to the other upon movement of said yoke by the blade.

8. A. shock absorber comprising a liquid containing housing, a wall atthe lower end of the chamber formed by the housing having oppositelyopening ports and edge notches forming channels for movement of liquidfrom one portion of the chamber to another, a shaft rotatable in thehousing having a radial ble de provided with a transverse opening, and ayoke movably mounted on the shaft having wings ex ending in spacedrelation with said blade to form compartments on opposite sides thereoland adapted to be moved by the rotating shaft and blade for movingliquid from one portion oi the housing to the other through said wall.

9. In a shock absorber a housin formim a cylindrical chamber, a wallextending across the lower end of the chamber having edge notches anddischar e ports provided with valves, rocking means in the housing formoving liquid toward said wall, and a split ring in said chamber havingan inner periphery eccentric to the axis of its outer periphery and aportion extending in said notches, said ring being movable by saidrocking means for controlling the QiIGClJlX G area of the notches.

10. In a shock absorber including a cylin- I drica'l liquid-containingchamber having an apertured partition and a shaft in the chamber,imperforate wings movable on the shaft, and a blade fixed to said shafthaving an opening for relatively free movement of the blade in thechamber, and adapted to move the wings against the resistance of theliquid.

11. In a shock absorber, a housing having a cylindrical inner wall, ablade mounted in the housing and having an edge slidable over said wall,a yoke movable by the blade having Wings spaced from the blade to formliquid containing compartments, and an arcuate partition Wall in saidhousing dividing the same into opposite portions and having openings forflow of liquid from one portion to the other upon movement of said yokeby the iade, said arcuate Wall being convex relative to the cylindricalinner Wall.

In testimony whereof I afiix my signature.

FREDERICK W. DAVIS.

